Photooxygenation Products of Bilirubin in the Urine of Jaundiced Phototherapy Neonates

Abstract

Phototherapy is widely and routinely used for treating hyperbilirubinemia (jaundice) in newborn babies. Neonates are irradiated with white or blue light to enhance the elimination of the yellow, potentially cytotoxic heme metabolite, (4Z,15Z)-bilirubin-IXα (BR).l Under normal metabolic conditions, BR is detoxified by conjugation in the liver and excreted in bile; however, when conjugation is impaired, BR accumulates in plasma and partitions into extravascular tissues, including the brain. It has been estimated that 2.5% of the live-born in the United States received phototherapy to remove or accelerate the excretion of BR from the ody and thus reduce the risk of BR encephalopathy.1